Hello everyone! I don't want to seem stupid, but how do you get rid of…

Hello everyone! I don't want to seem stupid, but how do you get rid of bad thoughts? The fear that the baby will be born with illnesses ?? After the ultrasound and tests everything is good, it's the first pregnancy, long-awaited, I am 27, it didn't work out because of karyotype and varicose veins in my husband. Now it seems like we should just forget about all this and rejoice, but the fear doesn't leave me ?